Pilot/Controller Glossary 

3/21/24 

nautical miles of the coast of the 48 contiguous States and Alaska, up to, but not including 18,000 feet MSL, 

and the airspace above FL 600. 
CONTROLLED AIRSPACE [ICAO]

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An airspace of defined dimensions within which air traffic control 

service is provided to IFR flights and to VFR flights in accordance with the airspace classification. 

Note: Controlled airspace is a generic term which covers ATS airspace Classes A, B, C, D, and E. 

CONTROLLED TIME OF ARRIVAL

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 Arrival time assigned during a Traffic Management Program. This time 

may be modified due to adjustments or user options. 
CONTROLLER

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(See AIR TRAFFIC CONTROL SPECIALIST.) 

CONTROLLER [ICAO]

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 A person authorized to provide air traffic control services. 

CONTROLLER PILOT DATA LINK COMMUNICATIONS (CPDLC)

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 A two

−

way digital communications 

system that conveys textual air traffic control messages between controllers and pilots using ground or 

satellite-based radio relay stations. 

CONVECTIVE SIGMET

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A weather advisory concerning convective weather significant to the safety of all 

aircraft. Convective SIGMETs are issued for tornadoes, lines of thunderstorms, embedded thunderstorms of any 

intensity level, areas of thunderstorms greater than or equal to VIP level 4 with an area coverage of 

4

/

10

 (40%) 

or more, and hail 

3

/

4

 inch or greater. 

(See AIRMET.) 
(See CWA.) 
(See GRAPHICAL AIRMEN’S METEOROLOGICAL INFORMATION.) 
(See SAW.) 
(See SIGMET.) 
(Refer to AIM.) 

CONVECTIVE SIGNIFICANT METEOROLOGICAL INFORMATION

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(See CONVECTIVE SIGMET.) 

COOPERATIVE SURVEILLANCE

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 Any surveillance system, such as secondary surveillance radar (SSR), 

wide

−

area multilateration (WAM), or ADS

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B, that is dependent upon the presence of certain equipment onboard 

the aircraft or vehicle to be detected. 

(See AUTOMATIC DEPENDENT SURVEILLANCE

−

BROADCAST.) 

(See NON

−

COOPERATIVE SURVEILLANCE.) 

(See RADAR.) 
(See WIDE AREA MULTILATERATION.) 

COORDINATES

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 The intersection of lines of reference, usually expressed in degrees/minutes/seconds of 

latitude and longitude, used to determine position or location. 
COORDINATION FIX

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 The fix in relation to which facilities will handoff, transfer control of an aircraft, or 

coordinate flight progress data. For terminal facilities, it may also serve as a clearance for arriving aircraft. 
COPTER

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(See HELICOPTER.) 

CORRECTION

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 An error has been made in the transmission and the correct version follows. 

COUPLED APPROACH

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An instrument approach performed by the aircraft autopilot, and/or visually depicted 

on the flight director, which is receiving position information and/or steering commands from onboard 

navigational equipment. In general, coupled non-precision approaches must be flown manually (autopilot 

disengaged) at altitudes lower than 50 feet AGL below the minimum descent altitude, and coupled precision 

approaches must be flown manually (autopilot disengaged) below 50 feet AGL unless authorized to conduct 

autoland operations. Coupled instrument approaches are commonly flown to the allowable IFR weather minima 

established by the operator or PIC, or flown VFR for training and safety. 

PCG C

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